Vapor electric device.



R. G. STANDERWICK.

VAPOR ELECTRIC DEVICE.

APPLIUATION FILED 0014, 1913.

L1 m wem Patented Feb. 9, 1915.

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REGINALD G. STANDERWICK, LYNN, MASSACHUSETTS, ASSIGNOR TO GENERAL ELECTRIC COMPANY. A CORPORATION OF NEW YORK.

VAPOR ELECTRIC DEVICE.

T all whom it may concern:

le it known that I, REGINALD G. S'rAisir.

ERWICK, a subject of the King of GreatBritain, residing at Lynn, in the county of Essex and State of Massachusetts, have invented certain new and useful Improvements in Vapor Electric Devices, of which the following is a specification.

The present invention relates to the operation of vapor electric devices, and particularly to the operation of mercury vapor devices of the high pressure type, such as the quartz lamp It is the main object of my invention to safe-guard the operation of vapor devices against excessive energy consumption and consequent overheating, particularly on series circuits.

The high pressure type of mercury vapor device ditlers from the low pressure type not only in the higher temperature and high efiiciency attainable by the use of a refrac tory envelop, but also in its electrical operating characteristics. For example, at a cer tain critical current value, the voltage consumption in the high pressure lamp increases steadily with but very little, or prac tically no increase in current. In other Words, if such a device were operated on an ordinary variable voltage, constant current circuit in the neighborhood of this critical current value, the voltage drop across the lamp would rise continuously until the wattage had increased to a point sufficient to destroy the lamp by excessive heating.

In accordance with my invention, a vaporelectric device having this peculiar voltampere characteristic is provided with an automatically controlled energy-consuming means, for example, a resistance, to divert current from the vapor device when the voltage consumed by the vapor device exceeds a predetermined limit by reason of an increase of current.

In the accompanying drawings, Figures 1 and 2 are diagrams illustrating a system in which energy is diverted from the vapor electric device by a magnetically-controlled resistance: and Fig. 3 shows an arrangement in which a self-reducing resistance is connected permanently across the lamp.

As shown in Fig. 1 a mercury vapor electric lamp tube 1, having a cathode consist; ing of mercury, or other easily vaporizable material, contained in a chamber 2, and an Patented Feb. 9, 1915.

' Application filed October 4, 1913. Serial No. 793,480.

' anode 3 of tungsten, or other highly refractory conductive material. is connected to conductors ft, and 5 which, for purpose of illustration, may be assumed to be fed by a variable voltage source. A high pressure lamp is commonly operated in a fused quartz envelop andis operated at high vapor pressure as described, for example, in Kiich Patent #883,725 of 1908, and an application, Serial No. 753,946, filed March 13,1913 by Dr. E. Weintraubl- The lamp is supported by straps 6 and 7, the former being rotatably mounted upon a fixed support 8 and the latter connected through a link 9 to the core 10, of an electromagnet 11. This magnet is connected in series with resistance 12, and contacts 13 and 14 to the lines 4 and 5. The contact 13 is connected to the armature of a series magnet 15 and the contact 14 is controlled by magnet 16 connected across lines i and 5 by conductor 17, in shuntwith the lamp. The lamp is started when a current of suitable voltage is applied by a rise of core 10 which tilts the lamp and causes a'flow of mercury along its length to make contact with the anode, thus completing a circuit through the lamp. The completion of an electric circuit in the lamp energizes the series magnet 15, which lifts its core thereby breaking the circuit of the magnet 11 and allowing the lamp to descend to its original position. An arc is thereby struck in theivell'known manner by the mercury receding to the cathode chamber.

As the lamp may be operated at highest efficiency near the critical value of current, it is desirable that the current maintained should be quite close to the current value at which the voltage begins to rise abruptly without further increase of'current. If any change in external conditions or of the electrical characteristic of the circuit should take place, tho lamp would be endangered by overheating. Should such a condition occur and the voltage consumption increase unduly, the magnet 16 will lift its armature,

completing a circuit through the coil 11 and resistance 12 in parallel with the lamp. The resistance of this circuit should be so proportioned that it Will shunt but a small part of the energy from the lamp, enough to reduce its temperature and vapor pres sure and restore it to normal operating'condition. In the case ofa 320 watt, four ampere quartz mercury lamp, the resistance of substantially constant current at variable voltage to said lamp, a resistance proportioned to carry afractional part of the energy consumed by said lamp at a given voltage and an electromagnet connected in shunt with said lamp proportioned to operate when the voltage across the terminals of the lamp increases above a critical value at which further increase of voltage is accompanied with little or no increase of current, and connections for shunting said lamp through said resistance when said magnet operates. a y

5. The combination of a 'high pressure vapor electric device, a resistance proportioned to consume a fractional part of the energy consumed by said device at a given voltage, means responsive to a rise of voltage on the terminals of said device above a predetermined value to connect said resistance in shunt with said lamp, a second resistance proportioned to carry sufiicient energy to extinguish said device when connected in conjunction with the first resistance in shunt with said device, and means for connecting said second resistance in shunt with said device when the operating current falls below a predetermined value.

6. The combination of a source of electric energy of substantially constant current, a high pressure vapor electric device connected thereto, and means responsive to a rise of voltage consumption of said device above the critical value at which an increase of voltage is accompanied by no substantial increase of current for decreasing the energy supply of said device while the voltage consumption exceeds this critical value.

7. The method of operating a high pressure vapor arc with a constant current variable voltage supply, which consists in normally maintaining the impressed voltage close to the critical value at which a further increase of voltage is accompanied by no substantial increase of current and when the voltage consumption tends to exceed this value substantially reducing the energy supply until the voltage consumption is decreased below the critical value.

In witness whereof, I have hereunto set my hand this 22 day of September, 1913.

REGINALD o. "sTrANnERWIoK.

Witnesses? JOSEPH H. ALLEN, Louis 'FRIEDMANN. 

